Distinct Changes in Calpain and Calpastatin during PNS Myelination and Demyelination in Rodent Models.

Myelin forming around axons provides electrical insulation and ensures rapid and efficient transmission of electrical impulses. Disruptions to myelinated nerves often result in nerve conduction failure along with neurological symptoms and long-term disability. In the central nervous system, calpains, a family of calcium dependent cysteine proteases, have been shown to have a role in developmental myelination and in demyelinating diseases. The roles of calpains in myelination and demyelination in the peripheral nervous system remain unclear. Here, we show a transient increase of activated CAPN1, a major calpain isoform, in postnatal rat sciatic nerves when myelin is actively formed. Expression of the endogenous calpain inhibitor, calpastatin, showed a steady decrease throughout the period of peripheral nerve development. In the sciatic nerves of Trembler-J mice characterized by dysmyelination, expression levels of CAPN1 and calpastatin and calpain activity were significantly increased. In lysolecithin-induced acute demyelination in adult rat sciatic nerves, we show an increase of CAPN1 and decrease of calpastatin expression. These changes in the calpain-calpastatin system are distinct from those during central nervous system development or in acute axonal degeneration in peripheral nerves. Our results suggest that the calpain-calpastatin system has putative roles in myelination and demyelinating diseases of peripheral nerves.

The Effects of Sildenafil and/or Nitroglycerin on Random-pattern Skin Flaps After Nicotine Application in Rats.

Smoking aggravates skin necrosis as a complication of random-pattern flap ischaemia. Sildenafil and nitroglycerin (NTG) are vasodilator agents that may affect skin flap survival. Fifty rats were subjected to a dorsal random-pattern flap operation and randomly divided into 5 groups. The control group received no treatment. The ischaemic group were administered local nicotine injections. The sildenafil group were administered oral sildenafil treatment in addition to the same intervention as the ischaemic group. The NTG group received topical NTG ointment application instead of sildenafil. The combined group were given both sildenafil and NTG treatments. After 7 days, all rats were sacrificed for flap assessment. Flap survival percentages at the 3rd and 7th days were significantly higher in the combined group than in the other study groups. Histologically, the ischaemic group exhibited dermal disorganization and inflammatory cell infiltration, which were improved in the 3 treated groups; however, the combined group presented the most relevant effect. The epidermal thickness showed a decrease in the ischaemic group (23.1 µm) that was significantly increased in the sildenafil (28.4 µm), NTG (28.8 µm) and combined (35.8 µm) groups. Immunohistochemically, the combined group exhibited a significant decrease in the apoptotic index and an increase in the proliferative index (2.3 and 56.9%, respectively) compared to those in the ischaemic (63.2 and 3%), sildenafil (41.7 and 28.1%) and NTG (39.3 and 30.4%) groups. Transmission electron microscopy (TEM) showed that the combined group displayed improvement in most of the ischaemic changes. Our analyses suggest that the combined use of sildenafil and NTG is more efficacious than using only one of these treatments for skin flap survival.

Photodynamic diagnosis of parathyroid glands with nano-stealth aminolevulinic acid liposomes.

Background The use of ALA to identify the parathyroid glands had been investigated both experimentally and clinically with promising results but the side effects from the systemic use of this photosensitizer reduce its widespread in clinical use. The aim of this study is to test the formulation of ALA in nano-stealth liposomes for better photodiagnosis of parathyroid glands intraoperatively with less ALA dose. MATERIALS AND METHODS: Preparation of ALA nanovesicles and in vitro characterization for the drug encapsulation percentage, vesicle size and Zeta potential then the study of nanovesicles stability and in vitro drug release profile was done. The study compared nano-stealth liposomes and nano-liposomes with the free ALA solution, intraperitoneal administration of these different ALA formulations in rats and observing the ability to identify parathyroids intraoperatively and evaluation of fluorescence differences between these groups. RESULTS AND CONCLUSION: Stealth liposomes were insignificantly higher in drug encapsulation%, in vitro drug release and zeta potential compared to conventional liposomes. Additionally, they needed less time for the start of the photosensitization and recorded the highest signal after spectrometry compared to the other two preparations. These data provide a new evidence of the potentiality of ALA-stealth Liposomes for identification of PTGs intraoperatively and could lead to propose a non-invasive procedure with reduced postoperative side effects.

Evaluation of the Effectiveness of Fluorescent Visualization of Bile Ducts Using Fluorescein and Ultraviolet A at Laparoscopic Cholecystectomy.

Background This work studied the diagnostic effectiveness of a new technology and device to augment visualization of bile ducts at laparoscopic cholecystectomy. It depends on excitation of fluorescein in bile by ultraviolet light to get green fluorescent light emanating from these ducts. Methods Forty laparoscopic cholecystectomy patients received fluorescein sodium injections either in the gallbladder or intravenously, followed by exposure of the expected bile ducts area to ultraviolet light that was delivered by a specially designed device. Neutral observing surgeons were asked to judge whether or not they could see fluorescent bile ducts early in the operation before they were displayed by dissection. Accordingly, specificity, sensitivity, likelihood ratios, and predictive values of the technique were calculated. Results Fluorescent bile ducts were seen at an earlier stage than their detection by dissection in 33 out of 40 operations. The technique had 100% specificity, 82.5% sensitivity, 0.18 negative likelihood ratio, 100% positive predictive value, and 85.11% negative predictive value. There were no complications related to the technique. Conclusions The developing ultraviolet/fluorescein technique is helpful in early localization of bile ducts at laparoscopic cholecystectomy. When fluorescence is detected in the field, the technique can be completely relied on to denote the position of bile ducts. In a few cases fluorescence is not detected. Here further development of the device is the need to improve its sensitivity. Otherwise, the technique is quite simple and safe.

Fluorescence-guided laparoscopic cholecystectomy: a new technique for visualization of biliary system by using fluorescein.

BACKGROUND: Safe cholecystectomy requires confident identification of extrahepatic biliary anatomy. This is the first report of the use of fluorescein and ultraviolet light to improve visualization of biliary topography during laparoscopic cholecystectomy. METHODS: Five patients who had symptomatic gallstones underwent laparoscopic cholecystectomy with intraoperative intravenous fluorescein injection. Ultraviolet A from an LED light source was used to induce fluorescence of bile. It was delivered by a device that was designed and built by the authors. RESULTS: Within 4 to 5 minutes the bile ducts were shining with green fluorescence and were easily differentiated from the surrounding tissues. In all cases, identification of the extrahepatic biliary anatomy by the fluorescence technique preceded its identification with conventional white light. Fluorescence remained for the whole duration of operation that extended for 42 to 77 minutes. CONCLUSIONS: At laparoscopic cholecystectomy, intravenous fluorescein injection and ultraviolet A excitation induce bile ducts to fluoresce. The technique allows better and earlier real-time visualization of biliary anatomy than conventional white light. The technique is simple and inexpensive. It serves as an additional tool that would improve safety of laparoscopic cholecystectomy.

Propranolol treatment of infantile hemangioma: clinical and radiologic evaluations.

BACKGROUND: There is no way to predict the size that proliferative infantile hemangiomas (IHs) can reach and to expect the occurrence of complications. Moreover, there are no well-known characteristics that can affect the rate of involution of IHs and to predict its completion. Accordingly, intervention is frequently indicated. Different modalities have been reported for treatment of IHs. The possible mechanisms of action of propranolol on IHs are complex. METHODS: Fifty infants presented with 80 IHs treated by oral propranolol at a dose of 2 mg/kg body weight per day. Treatment outcomes were clinically and radiologically evaluated. RESULTS: The first noticeable effects on propranolol treatment were the changes in color and softening of IHs, followed by regression of their sizes. The clinically elicited color changes of superficial IHs and superficial components of compound IHs have been objectively proven by statistically significant color clearance (P ≤ .001) and resisting index (P ≤ .01) (∼50% increase) as a good indicator of lower vascular activity within IHs. Moreover, the softening of lesions followed by the clinically elicited regression of sizes of deep IHs and deep components of compound IHs has been objectively proven by statistically significant changes at lesions' thickness (P ≤ .01) (∼50% regression) and resisting index (P ≤ .01) (∼50% increase). CONCLUSIONS: Collectively, high efficacy and tolerance of propranolol treatment have been elicited. However, propranolol treatment of IHs is still an issue suitable for more studies to confirm the safety and efficacy of the drug and to investigate whether there are some hemangiomas that are, perhaps, nonresponsive to propranolol treatment.

Non-excision treatment of multiple cutaneous neurofibromas by laser photocoagulation.

Neurofibromatosis type 1 (NF-1) is an autosomal dominant disorder characterized by skin tumours derived from peripheral nerves. It is a clinically diagnosed disorder of a mainly cosmetic concern. There are different excision modalities for treatment of cutaneous neurofibromas; however, none is considered to be universally accepted treatment. This study was conducted to evaluate a non-excision treatment of multiple cutaneous neurofibromas, using surface and interstitial approaches of neodymium:yttrium aluminum garnet (Nd:YAG) laser (1,064 nm) photocoagulation, depending upon the size and location of the lesions. Twelve patients with multiple cutaneous neurofibromas were included. Surface laser photocoagulation by long-pulsed Nd:YAG laser has been used for treatment of flat lesions, while interstitial laser photocoagulation by continuous wave (CW) Nd:YAG laser has been used for treatment of bulkier lesions. After 14 months of follow up, both approaches of laser photocoagulation have shown different success rates, as denoted by the regression of the lesions, an overall acceptable cosmetic outcome, and, generally, patients' satisfaction. Within the limitations of the present study, laser photocoagulation has proven to be a promising technique that may be an alternative or additive modality for treatment of multiple cutaneous neurofibromas. It is a minimally invasive, office-based technique that could be used safely and effectively, with a limited rate of complications. Surface laser photocoagulation has proven to be an effective tool for treatment of flat lesions, especially those located in exposed areas, with a favourable cosmetic result, while interstitial laser photocoagulation could be reserved for bulkier lesions, especially those located in non-exposed areas. However, further studies are necessary to refine the procedure, and to confirm the present encouraging findings, especially over a longer period of follow up, as well as to evaluate laser parameters for optimization of the technique.